Permission problems

I am using Drupal 6.6, and have just installed and enabled the flexifilter module. At first, I did not see Flexifilter as an item under Site Building on my admin page. And if I tried to go directly to /site/build/flexifilters, I got an Access Denied page. I checked permissions, and don't see any permission settings for flexifilter - in fact, my role has permissions turned on for every single item on the permissions list.

I then tried logging in as the #1 admin user, and then the Flexifilters link was revealed on the admin page. I was able to get to the first page, which showed enabled filters (only Mediawiki listed here), but when I click on "Edit" for the Mediawiki format, I get an Access Denied page.